In the last post (It’s Full of Galaxies) we saw an infrared image from the Herschel space telescope looking at a tiny piece of the cosmos revealing thousands of galaxies 10 – 12 billion light-years from us.  The image below is also an infrared image, but it is a view of millions of galaxies as taken by the 2MASS (Two Micron All Sky Survey) looking across the night sky.

      The blue band in the image comes from the stars in our own galaxy.  Note that the distribution of galaxies is not uniform, as one might expect but there are clusters, strings and webs of galaxies.  These structures are remnants of the big bang and the gravitational attraction between matter and the mysterious dark matter.  Think about this:  All of the matter we can see and account for in the Universe only adds up to about 4-5% of the total mass of the Universe!

     The  2MASS survey was conducted using two 1.3 meter telescopes, one in Arizona and the other in Chile, imaging the sky at 3 separate frequencies in the near infrared.  Imagine what this would look like if we were able to use telescopes in space that are above the filtering effects of our atmosphere in the infrared.

      Check these links for more information and a larger image.

Till next time,

RC Davison

      These are not stars but galaxies, thousands and thousands of them and each one containing billions of stars.  This snapshot from the Herschel infrared space telescope shows galaxies that are 10-12 billion years old with the red ones being the most distant.  The white  ones indicate galaxies with the greatest star formation.  Looking closely at the image one does not see an even distribution of dots/galaxies, which indicates that some of these galaxies were forming in clusters at that time.

     This image was one taken as part of the Herschel Multi-tiered Extragalactic Survey (HerMES) Key Project.  The purpose of the project is to study the evolution of galaxies in the distant cosmos.  This particular image lies in a region of space called the Lockman Hole, which is in the constellation of Ursa Major and provides a relatively unobstructed view into a far corner of the Universe.

     The next night you are out, take a look up into the night sky and think about the fact that all you can see is in the optical region of the spectrum.  Consider what lies beyond our narrow view of the vast cosmos.

Till next time,

RC Davison